Interchangeable unit camera



Marchl, 1936. F. w.l LUT z`A 2,036,061

v INTERGHANGEABLE UNIT cAuERA Filed Juiy 18, 19:55 2 sheets-sheet 1 1 'li HM VN l 'mi UM; Z/ tj'ln,

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ATTORN EYS Much 31,1936. F. www 2,036,061

.INT-ERCHANGEABLE UNlT CAMERA Filed July 18, 195s 2 sheets-snee; 2

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INVENTOR y YA ORNEYS Patented Mar. .31; 1936 to Fairchild Aerial Camera Corporation, Woodside, N. Y., a corporation ot New York Application Jilly 18, 1935, Serial N0. 31,962

t lclaims.

This invention relates ingeneral to cameras and more particularly toN cameras wlthinterchang'eable parts. n

In aerial photographic operations and especial- 'ly in vmapping projects where the negatives or contact prints are used in plotting machines, it is important that the exact location of the optical axis of the camera lens be recorded on the -negative or that the negative shall contain some reference points whereby this optical axis may be located with respect to the negative. This may be accomplished in one r more ways such as the photographing on the lm at the time of exposure, a markby Which-the exact location of the' optical axis of the lens on the resulting negatives is indicated. Another method of obtaining the desired result is to photograph on-the lm at the time of exposure reference points by which the exact location of the optical axis of the lens on .the resulting negative may be accurately'locatedby properly joining the reference points by a series of lines, the intersection of which will den'o'te the optical axis. The mark and the reference points may be photographed on the film either directly or by means of reiiecting mirrors or prisms.

In order to accurately locate these marks or` reference points on the negativeitr is necessary to have all `of the parts ofthe camera, the iiducial mark or plates to be photographed and also theA axis cannot be accurately located on the negative.

' In photographic operations it is often desirable to use lenses of various focal lengths and this in turn requires the use. of lens cones of corresponding lengths. Therefore, in rder`to`obt'ain the desired results, this has previously necessitated the use of a diilerent camera each time a lens o; different focaly length was used. This' would require a large ynumber of very expensive pieces of. equipment and for operation in the ileld would `add tremendously to the equipment necessary to be transported and kept on hand.'

If the lens cones were changed it would be necessary to collimate .the lens eauchrtimev and this would require extra equipment and would otherwise be an unsatisfactory operation. VFurthermore, the collimation of a lens is a highly delicate and precise ,operationfand requires great accuracy which cannot be readily obtained /in the ileld.

It is therefore an object of this invention to provide for ready interchangeability o! parts of a camera and still maintain the high degree of accuracy requiredin aerial photographic mapping.

More specically it is an object of this invention to provide means whereby ycamerasmay be used with cones for lenses of different' focal lengths and still maintain their proper relationship sothat the optical axis of the lens may al'- ways be accurately located on the negative or print for any and all cones that may be used.

Another object of the invention is to providel an improved means of producing on the illm, dur-A ing the exposurefv ducial:` marks or reference points for accurately locating on the print or negative the optical axis of any one oi a series of lenses.

.The camera may' take the form of the conventional aerialcamera comprising the usual main parts, such as the magazine, case and cone, th-

carried by a glass plate carried bythe case, this construction depending on the meansfor holding the film flat during exposure operation. The lm maybe held flat by such usual means as a pressure plate or a vacuum device for forcing. the film to lie flat in the focal plane.

In the event thatthe iiducial plates are carried by the camera case the ducial-plates according to v'my invention are preferably doweled to the case and the case in turn to the cone so that thef center of the area boundedby the plates will bear a constant relationship to the dowel pins joining the case and the cone. The drilling of the holes for the dowels should be accurately done while the camera-is held firmly in a Jig against any possible relative movement.A Then by the use of a collimator the optical axis of the 40 lens may be made to coincide with the exact cen-V ter of thearea bounded by the iiducial plates. This may be done by 'placing aglass plate upon which are lined cross hairs and these lines are Apositioned, with respect to the plates so as to 'make it possible to determine the exact center -oi 'the area bounded by the plates. By placing alight above a point at which the lines cross and by placing a container of Ymercury below the lens the point of lcrossing 'is thus projected 50 through thelens to the mercury and isv then reflected back. The lens is then shifted laterally until the reected image coincides with the actual point of crossing of the lines." When this coincidence occurs the optical axis of the lens is accurately located lwith respect to the area bounded by the flducial plates. The lens is then fixed in this adjusted position. Therefore, by reason of this relationship and since all lensjin all cones are collimated inja similar-manner, the

parts may be interchanged at will and the optical axis will still maintain its-relationship with the center of the area bounded by the fiducial plates.

The foregoing was merely one application of my invention, the exact nature of which will become more apparent on a'further reading of the followingspecication and appended claims, certain embodiments of the invention being illustrated in the accompanying drawings in which:

Figure 1 is a view in vertical section taken through an aerial camera showing the relationship between the magazine, case, cone and lens and showing the iiducial plates secured to the case.

Figure 2 is a view in top plan of the aerial camera with the magazine removed.

Figure 3 is a fragmentary vertical section through a portion of the-magazine and case showing the flducial plates carried by the magazine. Referring more particularly to the drawings: The camera is shown as comprising a magazine l in which are located the usual lm storage spool 2 and iilm winding spool 3 for advancing the lm a about the positioning rollers 5 and The photographic exposure area, is generally indicated at I and a means represents diagrammaticallya means of holding the nlm nat in the focal plane during the exposure operation. This means of holding the nlm ilat may be in the form of a pressure plate or of `a Vacuum device and Aeither means may correspond to that type in conventional use. The camera case S is shown devoid of working parts for the purpose of more clearly illustrating the manner in which the magazine is secured thereto and also the manner in which the cone I0 is secured to the case. As is customary, the lens case II is carried by the cone and the case I I in turn carries a lens I2. l

In the illustration shown in Figures l and 2 the iiducial plates I3, having reference slots I3', are aligned With the camera case by doweling and by the use of attachment screws Ifl. Four of the fiducia] plates are shown equally and radially spaced with respect to the center of the exposure area and projecting into the exposure area. The iiducial plates are shown disposed at right angles to each other. The important point is that they be radially disposed so that the lines projected therefrom inwardly will intersect at the true center of the'exposure opening or the area bounded by the ducial plates. Prior to or after the arrangement of the doweling and/fastening of thev fiducia] plates, the camera case and the cone are placed in a jig while drilling holes in the camera case and in the cone for the joint reception or" .common dowel pins I5 in order to accurately align accuratelyv located with respect to the area bounded by the iiducial plates, the lens is thi n fixed in this position by drilling holes in the ar jacent surfaces I 6 and I l of the lens case and the cone, respectively, for the reception of a plurality of aligning dowel pins I8.v This also predeterminedly positions the lens with respect to the dowel pins I5. The camera is of the betweenthe-lens shutter type, the shutter not being shown for purposes of clarity. As long as the ducial Aplates are carriedbyT the case it is not optical axis with the negative is determinable v from them. A slight misalignment of the maga- '-zine, therefore, with respect to the case, will have no eiect upon the accurate location of the optical axis on the resulting negative or print.

If, however, it becomes desirable to locate the iiducial plates in the magazine, it follows that the magazine would then necessarily have to be accurately positioned with respect to the case and the cone, keeping the center of the area bounded by the plates properly positioned with respect to. the dowel pin of the case and cone. Such an arrangement is shown in Figure in which the iiducial plates are doweled to and secured to the magazine base I9 by screws 50. The magazine base I9 and the upper end 20 of the the case 9 are doweled for the reception of .vertically extending dowel pins 2| for maintaining this predetermined and proper aligned-relationship between the magazine and the case transversely. A similar doweling operation and the use of transversely extending retractable dowel pins 6B maintains the proper aligned relationship between the magazine and the case vertically.

The lens assembly may be suitably secured'to the lens case in non-adjustable relationship by means of a plurality of bolts 22. As shown in Figure 2, the case portion 23 is provided with a slot 26 of substantially greater width than that of the ducial plate I3, leaving room for relative slidingmovement of the ducial plate therein for adjustment before it is doweled to the case and fixed thereto by means of the screws EQ.

This is for the purpose of permitting accurate positioning of the four'iducial plates with relation to the center of the area bounded by the plates.

It is, of course, necessary to provide additional means for securing the magazine to the case irrespective' of whether the magazine is doweled to the case or not. Such means may comprise a suitable ring 25 carried by the magazine and secured by screw bolts 25 to the case. The'same is true with respect to the alignment and the securing of the case to the cone. In the latter instance, the cone may be provided with suitable fastening means in* the form of screw bolts 26 at spaced positions for releasably securing the case to the cone. For the purpose of providing easy access for these doweling operations the' cone may be cut away atv28 as shown in Figures l and `2. That portion represented as a boss at 29 of the cone is then not only adapted to 1 receive the dowel pins I5 but screw bolts 26 as well for aligning and securing the same with the case. Obviously the holes in the case for receiving the screw bolts 26 are not drilled until after the holes for the reception of the dowel pins are formed and the dowel pins have been located therein for insuring the proper alignment in accordance with the foregoing description. Subsequent also to the doweling operation for maintaining the proper relationship between the lens case and the cone, there are drilled suitable holes in the lens case and cone to receive screw bolts 3U for securing the lens case and cone in proper relationship aligned by the dowel pins.V It will be noted that the'outside diameter of the lens case il is appreciably less than. the inside diametero! the collar 32 for receiving the lens case. The space ll therebetween allows for lateral movement of the lens 'case on the cone during the collimating operation prior to the drilling ofthe holes and the positioning of the dowel pins i8.

This lateral movement of the lens case on the cone is further restricted by the'space Il between the extension I5 of the. lens case and the adja-l cent shoulder 3i of the cone. Whichever of the v ,-two'spaces 34 or I3 is lesser will limit the lateral 'tained a light-tight relationship so as to prevent f faulty photographic exposure. More specifically,

" this light-tight relationship is accomplished by the angular light trap between the adjacent base I9 of the magazine and the upper end 20 of thecase upon which the magazine rests. The leakage of light is also lavoided by the snug engagement of the flange 50 of the magazine base by a flange 52 formed at the lower end of the magazine cover 5l, In the event that the fiducial plates are carried by the magazine as indicated in Figure 3 it may be found possible to ,so accurately align the magazine with-respect to the case that thedoweling operation and the dowel pins may be dispensed with. 'Ihis willprobably be found to be a more dimcult operation than the doweling operation already described. In the event, how,-

ever, that such an alignment without dowel pins is found to be eifective the relationship between the magazine and the case will not only be a lighttight relationship but an aligned one as well. The abutting portions of the magazine base I9 and the upper end 2li of the case form an angular light trap.

The same Ything holds true insofar as the aligned relationship between the case and the cone isv ncerned. Inother words, the adjacent shoulders of the portion 31 ofthe cone and the shoulders 38 and 39 of the case should be in `light-tight relationship and these shoulderspro- .vide an angular light trap to prevent leakage of light. A

In the` event that the doweling operation and the provision of the dowel pins is carried out in accordance with the foregoing description in this respect this relationship, while being light-tight, shouldprovide suficient leeway for a slight relative movementbetwe'en 'the case and the cone to permit accuratel'alignment and the subsequent doweling operation. In the event, however, that I may desire to dispense with the doweling operation, I may nd it possible and expedient ,to otherwise align the vcase with the cone and provide the 'adjacent portions' of the case and the cone in such a manner that 'they will maintain not only a light-tight relationship between the case and the cone but also provide and maintainan equal relationship between the case and the cone so that it will only be necessary to secure the two together,hymeanav f bolts such as shown at aand 2 1.` s W -l The above description 4,is merely exemplary of different means for alining and maintaining an-accurate relationship between the iilm and the lens regardless of the size or shape of the said camera.

cone or magasine secured to the.,case. The im- DOrtant and novel feature of the invention resides in so correlating a series of cones so that the means for aligning and connecting the cone to the c asevwill bear a predetermined and unalterable relationship with the optical axis of Athe lens, lorg/in other words, to the center of the area bounded by the iiducial plates in case'the latter are' used. In this lconnection it is to be understood that the fiducial mark may be registered on "the lm in other ways than by the use of the flducial plates. For instance, the fiducial mark may be registered on the film by reflecting anv carrying cones, said camera having an exposure opening, means for producing iiducial marks von the photographically sensitized surface, employed by said camera, during the exposure operation, said means being in predetermined non-adjustable aligned relationship in each of said cases, a

lens carried by each of said -coz'es in predetermined, non-adJustable aligned position with respect to said means for producing said ducial marks when each of said cones is assembled in said camera, each of said cases and cones, when assembled in said camera, being in predetermined, non-adjustable aligned position'with respect to eachother and to said means for producing said ducial marks, and predeterminedly adjusted means for causing each of said plurality of interchangeable cases and cones carrying said lens to automatically assume and maintain said predetermined relationship when assembled in 2. In combination with a camera, a plurality of interchangeable magazines, cases and lenscarrying cones, said camera having an exposure opening, means for producing flducial marks on the photographically sensitized surface, employed by said camera, during the exposure operation, said means being in predetermined, nonadjustable aligned relationship in each of said zines and corfes carrying said lenses to automati-V cally assume and maintain said predetermined relationship when assembled in said camera.

,3. In combination with`acamera, a plurali- -ty of interchangeable magazines, vcases and cones,

said camera having an exposure opening, means for producing flducial marks on the'photographically sensitized surface employed by' said camera during the exposure. operation, said means being predeterminedly aligned and positioned within said camera, predeterminedly adjusted means for causing eachof said interchangeable magazines, cases and cones toautomatically assume apredetermined aligned relationship to each other and to the means for producing said-fiducial marks, lenses carried by each of said cones in predeterminedly 'adJusted relationship to said last named means.

4. In a camera, a magazine, a case, a cone, a lens and lens case carried by said cone, said carnera having an exposure opening, means for producing iiducial marks on the photographically sensitized surface employed by said camera during the exposure operation, said means being equally and radially spaced with respect to the center of said exposure opening, predeterminedly adjusted means for causing said case, cone and lens to automatically assume a predetermined aligned relationship to said center of said exto said marks when produced.

6. In combination with a iilm camera, a plurality of magazines, cases and cones, a lens and lens case carried by each of .said cones, means for producing ducial marks on the ilm during the exposure operation,'each of said magazines, cases .and cones of said camera being ,adapted to be removably secured to each other in predetermined aligned relationship to each other and to said means for producing said fiducial marks, said lens being secured in each of said cones in predetermined aligned relationship to said means for producing said fiducial marks, predeterminedly adjusted means for causing each of said maga` zines, cases and cones to automatically assume said relationship when in assembled position.

7. In combination with a lm camera, a plurality of interchangeable magazines, cases and cones, a lens and lens case carried by each of said cones, means for producing `fiducialrmarks on the` nlm during the exposure operation, said magazine, case and cone of said camera being removably secured to each other in predetermined aligned relationship to each other and to said means for producing said iiducial marks, preadjusted means for causing each of said magazines, cases and cones to automatically assume said relationship lWhen rin assembled position, said lenses being secured in said cones in predetermined aligned relationship to said last named means.

8. In combination with a film camera, a plurality of interchangeable magazines, cases and cones, a lens and lens case carried by each of said cones, means for producing iiducial marks on the iilm during the exposure operation, said magazine, case and cone of said camera being removably secured to each other in predetermined aligned relationship longitudinally and transversely to each other and to said means for producing said ducial marks, said lenses being secured in said cones in predetermined aligned relationship to said means for producing said ducial marks, predeterminedly adjusted means for causing each of said magazines, cases and cones to automatically assume said relationship when in assembled position.

9. In combination with a lm camera', a .plurality of interchangeable magazines, cases and cones, a lens and lens case carried by each of said cones, said camera having an exposure opensurfaces for causing each of said magazines, cases and cones to be removable and to automatically assume a predetermined relationship longitudinally and transversely to the center of said exposure opening when in assembled position.

l0. In a camera,- a magazine, a case, a cone, a lens and lens case carried by said cone, said camera having an exposure opening, means for producing iducial marks on the photographically sensitized surface employed by said camera during the exposure operation, said means being equally and radially spaced with respect to the center of said exposure opening, predeterminedly' adjusted means for causing said case, magazine cone and lens to automatically assume a prede termined aligned relationship to the center o said exposure opening when in assembled position. A

1l. In combination with a lm camera, a plurality of interchangeable magazines, cases and cones, a lens and a lens case carried by each of said cones, means for producing fiducial marks on the film during the exposure operation, each of said magazines, cases and cones being adapted to be removably secured to each other in prede-A termined aligned relationship longitudinally and transversely 'to each other and to said means for producing said iducial marks, predeterminedly adjusted means for causing each of said magazines, cases and cones to automatically assume said relationship when in assembled position in said camera, said lenses being secured insaid cones in predetermined aligned relationship to said last named means. Y

l2. In combination With a film camera, a plurality of magazines, cases and cones, alensrand lens case carried by each of said cones, means for.

producing iiducial marks on the vfilm during the exposure operation, each of said magazines, cases and cones of said camera being adapted to be removably secured to each other in predetermined aligned relationship to each other and to said means for producingsaid flducial marks, predeterminedly adjusted means for causing each of said magazines, cases and cones to automatically assume said relationship when in assembled position, `said lens being secured in eachbf saidcones in predetermined aligned relationship to said last named means.

13. In combination with a film camera, a plurality of interchangeable magazines, cases and cones, a lens and case carried by each of said cones, means for producing iducial marks on the film during the exposure operation, said lenses eing secured in said cones in predtermined alig ed of said magazines, cases and cones to autmat- 'ically assume said relationship when in assembled position in said camera.

FREDERICK W. LUIZ. 

